Heard victim beg (4)
I believe the answer is:
Here is my best explanation:
'beg' is the definition.
('pray' can be a synonym of 'beg')
'heard victim' is the subsidiary indication.
'heard' indicates a 'sounds like' (homophone) clue.
'victim' becomes 'prey' (prey is a kind of victim).
'prey' sounds like 'pray'.
(Other definitions for pray that I've seen before include "Implore", "Offer supplication", "Devoutly hope", "Address God", "Speak to God", "Wish earnestly (for a particular outcome)", "Supplicate, entreat", "Hope strongly", "Beg" and "Ask earnestly (for)".)